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Cooling a garage

bobjm | Posted in General Questions on

My garage is about 800 sq ft with 12 ft ceiling. I have my workshop in the garage. I want to make it more comfortable on hot days. The POA will not allow an exhaust fan in the wall.
Looking for suggestions.
AC not an option.
I was thinking exhaust fan in the ceiling with an attic fan (same cfm as exhaust fan) to prevent positive pressure in attic.

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  1. GBA Editor
    Martin Holladay | | #1

    If the Property Owners Association won't allow a wall-mounted fan, the next step would be to ask if they will accept a roof-mounted fan. Of course, a fan won't cool your garage below the outdoor ambient temperature -- you need AC for that.

  2. bobjm | | #2

    I understand I cannot get below outdoor ambient. But if upper garage temp is 100 and outdoor is 90, I would like to replace the 100 with 90.
    Let clarify my question.
    If I put an exhaust fan in the garage ceiling, I can remove the higher temp air and replace it exterior ambient. But now I am increasing the pressure in the garage attic.
    My question: should I put in a roof fan matching the cfm of both?

  3. Expert Member

    If you are allowed a vent termination for a roof fan, why not just duct the ceiling fan directly to it, rather than venting into the attic and then out again?

  4. curtkinder | | #4

    Find a new POA.

    Be careful not to overly depressurize the attic over living space unless you are extremely confident that the ceiling between the conditioned space and attic is substantially air tight (that's hard to guarantee without specific knowledge and specialized equipment.

    Despite your remark that "AC is not an option" the best approach if you are serious about a comfortable garage workshop is probably a suitably sized ductless minisplit with the outdoor unit in a POA-friendly location is probably the best answer.

  5. GBA Editor
    Martin Holladay | | #5

    To expand on Malcolm's point, there are two possible approaches:

    1. You can install a ceiling grille connected to a duct boot, and install a duct that connects that ceiling grille to a roof-mounted fan.

    2. You can install a ceiling-mounted fan, and you can install a duct that connects that fan with a roof-mounted exhaust termination.

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